Tens of thousands of people across Australia are likely to be caught up in a major new epidemic of viral gastroenteritis, UNSW and Prince of Wales Hospital researchers have warned.
Scores of outbreaks caused by the highly infectious norovirus have already occurred in eastern Australia, in some cases forcing hospitals to close their doors to visitors.
People in large families and in group settings - including nursing homes, hospitals and childcare centres - are most at risk. The infection causes vomiting and diarrhoea, usually lasting for about three days. No cure is available. Coming on the heels of the current influenza epidemic, the new spate of gastroenteritis cases is likely to afflict businesses with another wave of sick leave.
A team led by UNSW virologist Peter White has identified the mutant virus responsible, called the 2006b norovirus strain.
"In the last 10 years we have seen global epidemics of norovirus in 1996, 2002, 2004, and 2006. Last year's wave of outbreaks was predominantly caused by a different virus termed 2006a, although 2006b was circulating. Now it appears that 2006a has disappeared and 2006b has emerged as a major health concern," Dr White says.
The 2006b norovirus has been "genetically fingerprinted" as the source of outbreaks now occurring in Queensland, Adelaide and New South Wales, including the Hunter region north of Sydney. The epidemic is likely to spread across the country over the next few months warns UNSW virologist Peter White, who identified the virus with colleagues from the Prince of Wales Hospital.
The epidemic could result in hundreds of outbreaks affecting tens of thousands of people in every state, Dr White says. "We are seeing a wave of multiple outbreaks that is already spreading across Australia," Dr White says.
Spread by air, water and personal contact, noroviruses are highly contagious and can survive in food, water and the environment for long periods, according to Prince of Wales senior virologist, Bill Rawlinson, one of the research authors.
"The virus can be spread by person-to-person contact. It can be passed on by shaking hands with someone, for example, who has been sick and has the virus on their hands. It can also be picked up from contaminated surfaces, food or drink, and it's possible that infection can spread through aerosol particles when people vomit," he says.
Noroviruses have accounted for a five-fold increase in infectious gastroenteritis cases in recent years. They cause up to 90 percent of infectious gastroenteritis cases globally each year. Public health experts have been puzzled by the periodic emergence of new strains of the norovirus, which causes rapid-fire outbreaks of gastroenteritis across the globe before suddenly vanishing again.
Media contacts: Dr Peter White: 02-9385 3780, Dan Gaffney: 0411 156 015.